Diamond holder



Aug. 18, 1942. J. DlNHOFER DIAMOND HOLDER Filed March 31, 1942 INVENTQRJulizw fillnh fer B TORNEY Patented Aug. 18, 1942 UNHTED STATES E' ATENTOFFICE DIAMOND HOLDER.

Julius Dinhofer, New York, N. Y.

Application March 31, 1942, Serial No. 437,077

Claims.

This invention relates to holders for diamonds and other gemsparticularly when the same are to be worked or polished and has for itsprimary object the provision of means by which the gems may be securelyheld during the grinding or polishing operation, or for other purposes.

More particularly, the invention contemplates the provision of a stemfor reception in a chuck or other holding device, said stem having aseat adjustable extensibly out of one of its ends, and a rotativelyadjustable member carrying movable clamping fingers for holding the gemagainst the seat. The invention further contemplates the provision ofmeans for adjusting the clamping fingers to maintain the same inclamping position to thereby engage and firmly hold diamonds ofdifferent sizes against the seat, and also in means by which saidfingers and the mounting therefore are capable of fixture in anyselected position of engagement with the diamond.

In the accompanying drawing, wherein an embodiment of the invention isshown, Fig. 1 is a side elevation of a diamond holder constructed inaccordance with the invention; Fig. 2 is a vertical sectional viewthrough the device; Fig. 3 is a side elevation of the device at rightangles to that of Fig. l, and Fig. 4 is a sectional view on the line 4-4of Fig. 3, looking in the direction of the arrows.

In the drawing, I indicates the stem of the holder, said stem beingadapted to be received and held in the chuck of the conventional supportfor holding the device in the required manner to present the surfaces ofthe diamond 2, held by it, against the surface 3 of the polishing Wheelor other operating structure. Provided in one end of the stem is aninternally threaded recess 6 for the reception of a screw 5 having ahead 6 constituting a seat for the top surface of the diamond. The topsurface of the head, while shown flat to accommodate the top face of thegem, may be recessed or otherwise shaped to fit any other portion of thegem.

Surrounding the stem I is a block 1 which is loose on the stem so thatthe same may be rotatively adjusted thereon and set in any selectedposition of adjustment by means of the set screw 8. Pivotally mounted atthe opposite sides of the block I is a pair of fingers 9, each of saidfingers being pivoted on a pivot pin It. The outer ends I8 of each ofthe fingers is curved inwardly so that these ends of the fingers overliethe top or head of the screw 5 and co-operate therewith in holding thediamond, as clearly shown in the drawing. The inner ends II of thefingers are connected by a torsional coil spring I2 tending to normallydraw the inner ends of the fingers toward one another and to resultantlyspread the outer or free ends I8 of the fingers apart.

Provided on the stem I is a threaded portion I3 for the reception of anut I4 having a circular finger-engaging portion l5 and a conical camsurface it. The latter surface is operative against the portions ll ofthe fingers 9 so that by manual adjustment of the nut I4, the outer endsof the fingers will be caused to move inwardly or toward one anotheragainst the tension of the spring I2, and caused to engage against thediamond 2 and clamp the same against the seat 6.

The operation of the device is briefly as follows:

The diamond 2 is placed with its top surface against the seat 6, or, ifsaid seat is shaped complementarily to some other portion of the gem,such portion is placed in contact with the seat. By manipulation of theadjusting nut I4, the fingers 9 are moved to engage the surface of thegem and clamp the same securely against the seat 6. When it is desiredto shift the position of the fingers 9 relative to the gem, the setscrew 8 is loosened, the block 1 and the fingers 9 carried thereby isrotatively shifted and the set screw is then tightened to hold the blockin its new position. Since the screw 5 is adjustably extensible out ofthe end of the stem I, it will be obvious that by adjustment of saidscrew, gems of various sizes may be held in the holder, or the gem maybe so positioned in the holder to present more or less of its surface tothe grinding or polishing element.

Having described one embodiment of the invention, it is obvious that thesame is not to be restricted thereby but is broad enough to cover allstructures coming within the scope of the annexed claims.

What I claim is:

1. A diamond holder of the character described comprising, a stem, ablock on the same and capable of rotative adjustment on the stem, a seatfor one end of a diamond, said seat being adjustably extensible out ofone end of the stem, diamond-clamping fingers pivotally mounted in theblock and adapted to engage the diamond and clamp the same against theseat, means engaging said fingers and normally tending to separate theend portions of the same, and finger-adjusting means movable axially onthe stem for moving the fingers toward one another to cause the same toclamp the diamond against the seat.

2. A diamond holder of the character described comprising, a stem, aseat for abutment against one end of a diamond adjustably mounted in thestem, a block mounted on the stem and adapted for rotative adjustmentthereon, a set-screw for maintaining the block in any position ofadjustment relative to the stem, a pair of fingers pivotally mounted insaid block and adapted to clamp a diamond against the seat, a spring fornormally forcing the free ends of said fingers away from each other, andan adjusting element movable axially of the stem for engagement againstthe fingers to force the free ends of the same toward one anotheragainst the tension of the spring,

3. A diamond holder of the character described comprising, a stem havinga threaded portion, a seat at one end of the stem and adjustable in andout of the stem, a block rotatively adjustable on the stem adjacent tothe seat, means for fixing said block in any position of adjustment, apair of curved fingers pivotally mounted in the block, said fingers eachhaving a free outer end for engagement against a diamond to clamp thesame against the seat, a coil spring surrounding the threaded portion ofthe stem and connecting the thereon, said adjusting nut being providedwith'a' cam surface operative against the inner ends of the fingers toforce said inner ends of the fingers away from one another against thetension of the coil spring.

4. A diamond holder of the character described comprising, a stem, ascrew at one end of the stem having a head forming a seat for the top ofa diamond, a block supported on the stem, a pair of fingers pivoted inthe block and having free ends for engagement against the under portionsof the diamond to clamp the diamond against the seat, spring meansengaging the inner ends of the fingers to normally force the free endsof the fingers away from one another, and cam means movable axially ofthe stem and operative against the fingers to cause the free ends of thesame to be moved toward one another against the tension of the spring.

5. A diamond holder of the character described comprising, a stem havinga threaded portion, a screw adjustable in one end of the stem, saidscrew having a head forming a seat against which the surface of adiamond is held, a block on the stem surrounding the screw, a pair offingers pivoted in the block and having free ends overlying the head ofthe screw for engagement with surfaces on the diamond to clamp thediamond against the seat, the opposite ends of the fingers extendingbeyond the block and being connected by a coil spring tending to drawsaid ends of the fingers toward one another, a nut received on thethreaded portion'of the stem and adjustable thereon, said nut beingprovided with a conical cam surface entrant between the springconnectedends of the fingers to engage against said ends and force the same apartagainst the tension of the spring which connects them.

JULIUS DINHOFER.

